Spring clips are often used alone or together with other fastening elements in many shapes and sizes for connecting components. They mostly consist of spring steel or a high-strength, elastic material and are in general shaped so that they are capable of assuming within elastic limits two differing final shapes, of which the one corresponds an engaging or releasing function and the other to the fastening function. It is often the case that the material properties of the spring clip are utilized not only to produce a positive interlock connection between two components but also to additionally or exclusively transmit forces between the components.
Thus, from DE 3303254 A1 for instance, a quick fastener for connecting two components provided with coaxial holes is known in which the actual fastening element comprises a U-shaped spring clip and a shaped pin. The spring clip is insertable through a fitting opening of the one component for connecting to this component by means of outwardly protruding tongues. On this first component a second component may be placed with an elastic seal sandwiched inbetween so that the hole in the second component is coaxially located with the hole in the first component or in the spring clip. Then, the pin needs to be introduced from above, splaying the spring clip and following rotation of the pin through 90.degree. the spring clip springs back into a latching position. In this arrangement the components are pressed against each other in the fitting direction by the spring clip whilst the pin inserted in the holes transmits the forces in a plane perpendicular to the fitting direction. Since the spring clip is not visible from without, there is no recognizing whether it is arranged in the intended position and whether with rotation of the pin through 90.degree. the desired fixing position and not, for instance, the release position is actually set. In intermediate positions too, the fastening function of the known device may be questionable.
A similar fastening device is known from GB 1465262 A, in which in addition to a spring clip and a locking pin further components belong to the fastening element which is thus substantially more complicated and expensive than the quick fastener as described before. From EP 0662559 A1 a fastener for releasably connecting two components is also known in which a spring clip is used which, however, is likewise multi-part and thus more complicated than the quick fastener requiring merely a spring clip and a pin.
All of the known fastening devices are thus hardly of any use when there is a need to connect two flat components with but a single fastening element so that they can be loaded in the fitting direction with substantial forces and are capable of assuring in a plane perpendicular thereto a mutual, dead-fit and durable location of the two components.